Compressor system and moisture separator therefor



Feb. 16, 1954 v COMPRESSOR SYSTEM AND M01 1.: SEPARATOR THEREFOR I Filed Feb. 6, 1952 2 Shat's-Sheet J.

I TOR. Alligrlasl lz mzdfin BY A TORNEY A. E. SCHMIDLIN 2,66%321 Feb. 16, 1954 s N I 2,669,321

COMPRESSOR SYSTEM AND MOISTURE SEPARATOR THEREFOR Filed Feb. 6, 1952 2 Sheets-Sheet 2 VINVENTOR.

Alberlzisz'sefimdfin iwM momm Patented Feb. 16, 1954 COMPRESSOR SYSTEM AND MOISTURE SEPARATOR THEREFOR Albertus E. Schmidlin, Caldwell, N. J.', assignor to Specialties Development Corporation, Belleville, N. .L, a corporation of New Jersey Application February 6, 1952, Serial No. 270,245

18 Claims.

The present invention relates to compressor systems for gaseous fluids such as air and the like embodying a moisture separator and liquid trap,

. with compressor systems for aircraft which systems are capable of functioning at below zero atmospheric temperatures such as encountered at high altitudes. In such systems air from the atmosphere is compressed, and the moisture in the compressed air is separated therefrom and is collected in liquid form in a trap from which the liquid is expelled periodically under the control of the compressor or apparatus associated with the compressor system.

In a practical installation of such a system on aircraft, the compressor and the moisture separator and/or trap may be located a considerable distance apart, thus requiring a substantial length of connecting tubing or conduit in which moisture may condense and collect when the compressor is idle. This condensed moisture will freeze at low temperatures and obstruct the tubing or conduit to thereby prevent flow of compressed air therethrough upon subsequent operation of the compressor.

Accordingly, an object of the present invention is to provide an improved compressor system which overcomes the foregoing difficulty.

Another object is to provide such a compressor system wherein the trap and/or moisture separator and the connecting tubing are purged by dry gas at intervals to expel moisture and/or liquid therefrom.

Another object is to provide such a compressor system wherein the purging is under the control of the operation of the compressor.

Another object is to provide an improved moisture separator and trap which is particularly adapted for low temperature operation.

A further object is to provide such a moisture E separator and trap which is simple and practical in construction, reliable in operation, and is readily manufactured and assembled in an economical manner.

,advantages not referred. toherein will'occur .to

one skilled in the art upon employment of the invention in practice.

In accordance with the present invention, the foregoing objects'are generally accomplished by providing a compressor system which comprises a compressor having an outlet; a storage receptacle to which compressed fluid from the compressor is to be supplied; a moisture separator and liquid trap having a compressed fluid inlet, an outlet connected to the receptacle, a drainage outlet and a valve for the drainage outlet including pressure operable means for normally closing the valve; conduit means connecting the compressor outlet with the separator inlet and the pressure operable means; a valve having an inlet connected with the compressor outlet and having a venting outlet; and means under the control of the compressor operable to effect closing and opening of the last mentioned valve.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

Fig. 1 is a. schematic view, partly in section, illustrating a compressor system including a moisture separator and trap and a control valve with the operating parts of the trap and the valve in the positions they assume when the compressor is idle.

Fig. 2 is a schematic view, partly in section, illustrating a portion of the system shown in Fig. 1 with the operating parts of the trap and the valve in the positions they assume when the compressor is in normal operation.

Fig. 3 is a detailed longitudinal sectional view of a moisture separator and trap embodying the present invention.

Fig. 4 is a sectional view taken along the line 44 on Fig. 3.

Fig. 5 is a sectional view taken along the line 5-5 on Fig. 3.

Referring to the drawings in detail and more particularly to Figs. 1 and 2 thereof there is shown a system for compressing and storing air at a pressure of about 3000 pounds per square inch. This system generally comprises a compressor l 0 having an outlet II; a moisture separator and liquid trap l2 having a chamber l3, an inlet Hi, an outlet IS, a drainage outlet l8 and a valve H for controlling the drainage outlet including pressure operable means such as a piston I9 and a piston chamber 20 for normally closing the valve; a valve 2| having an inlet 22 connected with the compressor outlet I I and having a venting outlet pressor'such as'shown 2,562,959 may be utilized wherein'the f nal cylinjcler of, the stage of compression is provided with the outlet H.

the valve members; and a spring fl'l acting on the piston to maintain the valve member off its seat.

thechamber inlet 14. age c0. l Q1 valve ii is rating chamber l3 r inlet l4 provided with a spring loaded check valve 28, which passageways are in communication with the other end of the tube 25 and each other; and a storage receptacle 29 connected to the separator outlet M by a conduit 30 having a check valve}! therein. v r V The compressor I0 is shown schematically as comprising a cylinder 35, a piston 36 anda rod 3'! connecting the piston to acrankshaft "39, but it will be understood that the compressor may be of any suitable design of either single or multiple stage type. In a practical installation, a comin my prior Patent No.

. The valveZl is also shown somewhat'sch ematcomprises a body tlll'formed icallyand'essentially at one 'end with a valve seat M communicating with the valve inlet 22, the venting outlet 7 its 'side,'and a'cylinder or piston chamber 42 at itsiotl'i er'end having'an inlet M; a valve member 45 for th'eseatM; a piston 46in the cylinder 42 The mean under the control of the compressor tor effecting closingand opening of the valve, in

addition to the piston 46 and the spring ll, in-

clude other elements responsive to the operation of the cgmpressor. These elements act to move the piston upwardly to cause the valve to engage its seat and shutoff communicationbetween the valve inlet 22 and its venting outlet 24 while the compressor is in normal operation, and act to permit the spring to move the piston downwardly to unseat the valve and establish communication between the valve inlet 22 and its venting outlet 24 when the compressor is idle or is operating at substantially below its normal speed. I

Such elements may be associated with the lubricating system of the compressor, which, for

example, generally comprises a path through which oil'is circulated, herein shown as a conduit BO'incommunicaticn with the cylinder inlet 44, and an oil pump 5| including a cylinder 52, a

piston and a rod '55 connecting the piston to the crankshaft 39 of the compressor.

In Fig. 1, the valve elements of'the system just described are illustrated in the positions they assume prior to operation of the compressor it). When the compressor is idle, the oil pump 5! also is idle and no oil is circulated through the conduit 50. Consequently, no pressure is exerted on the piston 48 by the oil and the spring holds the pistonin a position whereby the valve member 45 is oft its seat M to establish communicationbetween the valve inlet 22 and the venting outlet 24. Also, when the compressor is'idle, no

compressed air is flowing from the compressor outlet II to the moisture separator and liquid trap l2, whereby the check valve 28 shuts'off communication between the passageway 'Zl' and The position of the drainpl'e; as shown, may be off its'seat to'establish comimmaterial, butgfor exam- 'outlet'lfi (Fig.2); and the passageway 21 per square inch closes the valve I l.

munication between the chamber l3 and the drainage outlet it. Compressed air, if any, in the receptacle 29 is prevented from flowing through the outlet [5 and into the chamber [3 by the check valve 3|.

When the compressor I0 is put into operation, theoil in the lubricating system is pumped and the pressure thereof acts on the piston 4'5 to seat the valve member 45 and thereby shut ofi communication between the inlet 22 and the venting outlet *24 (Fig.2). Compressed air from the compressor enters the tube 25, the passageway 26 and the chamber 20 to raise the valve ll carried by the piston l9 and efiect closing of the drainage As the pressure in the tube 25 builds up, the valve 28 is unseated (Fig. 2) to admit air into the chamber l3 wherein separation of moisture therefrom is effected and the separated liquid is collected. The compressed air, from which moisture has been removed, leaves the chamber by way of the outlet l5, passes through the valve 3i and enters the storage receptacle 29. I a a When the compressor stops or is operated at'an abnormally low rate, the pressureoi the oil in the lubricating system drops to'a low value and the spring l'l acts on thepiston 26 to move the valve member 35 off its seat M and thereby establish communication between the valve inlet 22 and venting outlet 2 (Fig. 1). As this occurs, the tube 25, th passageways wand 2'? and the piston chamber 20 are vented, whereby the valve 23 closes and the valve ll opens (Fig. l). The pressure of the air in the chamber 1 3, upon opening of the valve ll, is effective to blow collected liquid through the drainage outlet 16 and thereby empty the trap. Prior to closing of the valve 28,

dry air in the chamber is rapidly released through the tube 25 to'purge the same of liquid which may have been condensedor collected therein to expel such liquid through the valve 2| to its venting tube 25 while the'compressor is idle and the system is subjected to below freezing temperatures.

It will be appreciated that, upon unclosing of the venting outlet vEl i, air in the conduit connecting the compressor outlet H and the valve inlet 22 'is relieved through the outlet 2t. Also, the check valve 3! closes when the air compressor stops to prevent return how of theair, in the storage receptable 29 and to thereby limit the quantity of air utilized in blowing out the trap and purging the tube 25.

In a practical installation of a system in accordance with the present invention, the valves ll, 2| and 28ers constructed and arranged to cooperate at predetermined pressures. When the compressor starts, the pressure or the oil of the lubricating system upon exceeding 20 pounds per square inch clos'esthe valve 2i and the pressure of th compressed air upon exceeding 150 pounds As the pressure of the compressed air 'buildsup to800 pounds per square inch, thevalve 28 opens and air passes through the separator to remove moisture and trap the same in liquid, state. Air pressure continues to build up to 3000 pounds per square inch,

and the compressed dry air is collected in the storage receptacle.

When the compressor stops or isoperated at a speed whereby the oil'pressure dropsbelow 20 ro nd er S u in h, t alien. ori nsfan the pressureof the airin'themoisture separator -:and .trap falls to 409 pounds per square inch'in about two seconds, whereupon the valve 28 closes. As the pressure of the air in the tube 25, the passageways 26 and 21, and the chamber 29 continues to drop to 150 pounds per square inch, the drainage valve I1 is opened by air at 400 pounds per square inch in the separator chamber I3, and this air blows out the trap. The air in the separator and the tube 25 continues to vent therefrom until the same is reduced to atmosphericv pressure. Referring now to Figs. 3 to 5, there is shown in detaila moisture separator and liquid trap I2, such as schematically illustrated in and described in connection with Figs. 1 and 2, wherein like elements are designated by like reference numerals. .This separator and trap structure generally comprises a tubular body part 69 providing the chamber I 3, a head 6| attached to the upper end of the part 69, and a base 62 attached to the lower end of the part 69. The base 62, as shown in Figs. 3 and .5, is a generally rectangular metallic block formed with a circular boss 64 at the top thereof which extends into the lower end of the body part 69 and which has an annular groove 65 for a gasket 66 providing a seal between the body part and the base. The boss also has a conical liquid collecting recess 61 which is formed with a central drainage opening 69 at the bottom thereof having a valve seat 68.

The base 62 is further formed with an enlarged vertical bore 19 extending from the opening 69 to the bottom, a horizontally extending bore 1I (Fig. 3) which intersects the bore 19 adjacent the lower end thereof having one end in communication with the tube 25, a vertical bore 12 in communication with the other end of the bore 1|, a horilzontally extending bore 14 communicating with the bore 19 adjacent the opening 69 and serving I. as the drainage outlet, a horizontally extending bore 15 for an electrical heater 16, and a recess 11 (Fig. for housing a thermostatically controlled switch 19, the purpose of which will become apparent hereinafter.

A. plug 99 is threadedly secured in the bore 19, and is formed with a central bore serving as the chamber 29 for the piston I9 carrying the valve member I1 which is positioned to engage the seat 68.

Diametrically opposite openings 8 I, at the lower end or the piston chamber bore 19 and in alignment with the bore 1I (Fig. 3) establish communication between the piston chamber I3 and the bore 1| and establish communication between the opposite ends of the bore 1|, whereby compressed air entering the bore H from the tube 25 will cause the piston I9 to raise the valve member against its seat 68 and will flow to the bore 12.

The head 6!, as shown in Figs. 3 and 4, is a generally rectangular metallic block formed with a circular boss 84 at the bottom thereof which extends into the upper end of the body part 69 and which has an annular groove 85 for a gasket 86 providing a seal between the body part and the head. The boss also has a central vertical bore 81 in which a depending tube 88 is mounted to serve as the inlet for the chamber I3, and has an annular groove 89 surrounding the lower end of the bor 81 in which a depending tube 99, slightly shorter than the tube 88, is mounted to serve as the outlet for the chamber, as about to be described. I The head 6| is further formed with a horizontally extendingbore 9!, a restricted bore 92 -.Qonnectines. he;bores1 Blend 91 andtaneent all .:c ose atabout iii-.352 and-.1 9 s aniel; .abqu figi disposedwith respecttothe bore 8.1 to serve as av nozzle forv imparting swirling motion to compressed air entering the tube 88 whereby mechanical separation of moisture from the air is efiected, a vertical bore 94 in communication with the bore 9| and in alignment with the bore 12 of the .base, a horizontally extending outlet bore. 95. to which the conduit 39 is connected, a vertical bore section 96 (Fig. 4) connecting the bore and the groove 89, and a horizontal bore 91 adjacent the bore 81 for mounting an electrical heater 98.

The bore =9I has an open end in which a plug I99 is threadedly secured, and has a closed end opposite the open end. The plug I99 is formed with. a valve seat I9I at its inner end against which the check valve member 28 is held by a spring I92 in the closed end of the bore 9|, and has a duct I93 extending therethrough for establishing communication between the bore 94 and the valve seat opening.

In order to connect the base bore 12 and the head bore 94 whereby compressed air is conducted from the tube 25 to the chamber inlet I4, a tube I94 has its ends extending into the bores 12 and 94, respectively, and suitable means are provided for forming a seal between the ends of the tube and the base and head, respectively. Such means preferably include a packing such as a small O-ring I95 facing the end of the tube I94, and a short tube section I96 extending through the O-ring and into the tube I94 and a restricted portion of the bores 12 and 94, respectively. This arrangement provides a tight seal as well as a floating connection between the bores 12 and 94 whereby the length 01 the tube vneed not be maintained within extremely accurate dimensions.

As previously indicated, the head 6| and base 62 are attached to the body part or tube 69. This is accomplished in a convenient manner by forming the head and base with aligned apertures I91, and mounting bolts I99 in these apertures which have heads II9 engaging the underside of the base andhave their upper ends threaded into the apertures I91 of the head.

' The separator and trap structure as described so far, preferably is encased in a heat insulating housing. This housing may comprise a tubular shell I II having a mounting bracket I I2 attached thereto, and an upper cover I I4 and a lower cover II5 engaging the respective ends of the shell. In order to connect the shell and-covers to the encased separator and trap structure, screws H6 extend through the upper cover H4 and are threaded into the head 6| to hold this cover against the upper end of the shell, and screws I I1 extend through the lower cover I I5 and are threaded .into. the base 62 to hold this cover againstthe lower end of the shell.

, The purpose of the heaters 16 and 98 is to preventmoisture or liquid from freezing in the bores .of the head and base, particularly in the nozzle 92 and the drainage opening 69, but by constructing the head and base of metal, heat will be conducted throughout the head and base to prevent .freeze-ups in other bores or passages thereof. These heaters are of the resistance type, and are connected in an electrical circuit under the control of the switch 19 which in turn is electrically connected to a connector II9 mounted on the lower cover I I5 for plugging in a source of electrical energy. The heater thermostat or switch 19 may be constructed and arranged to an inlet connected'with whereby the temperatur'e of the head and 'base is always well above "the freezing point of water.

The separator and trap 'structu're illustrated in Figs. '3 tot operatesin-the' sa-me manner as the separator and trap l2-of -the" "system to expel trapped liquids atintervals in response 5 to the action of the compressor and to purge connecting conduits between the separator and'the compressor outlet to prevent freeze-ups whil'ethe compressor is idle.

As various changes maybe made in the forin,

construction and arrangement of the 'parts herein, without departing rrom the spirit and scope of the invention and without-sacrificing'any of its advantages, it is to be understood that all matter herein is to bo-interpreted -as illustrative and not in any limiting sense.

I claim:

1. In a compressor system of the class 'described, the combination "of a compressor having an outlet; a 'stora'gereceptacleto which compressed fluid fromsaid co'mpressor is tobe sup: plied; a moisture separator havinganinletjan outlet connected to said recepta'c'le, a drainage outlet and a valve for cluding pressure operable -means for normally closing said valve; conduit 'meansconnecting said compressor outlet with said separator inlet and said pressure operable meansg a valve having :said 'compress'or outlet and having a venting outlet; and 'me'ans under the control of said' c'ompre'ssor 'operable to eiiect closing and opening of said mast-mentioned valve.

2. In -a compressor system of the class-described, the combination-of 'a compressor having an outlet; --a storage receptacle to which 'compressed fluid from said 'compress'or is to be'supplied; a moisture separator -having an-inlet, an outlet connected to said receptacle, a drainage outlet and a valvefor said 'drainage outlet in- "cluding pressure operable means "for closing-said valve conduit means connectingsaid compressor outlet'withsaid separator inlet and said pressure operable means; avalv'eha'ving an inlet connected with said*compressonoutlet, a venting outlet and a valve member for controlling the flow of fluid from said valve inlet to saidventing outlety'andmeans under the control ofsaid compressor for operating said valve'member.

3. In a compressor system of the classdescribed, the combination of a compressor having an outlet; a lubricating system for said compressor wherein' the lubricant is rpressurizedya storage receptacle'to'which compressed fluid'from said compressor'is-tobe suppliedya-moisture separator having an inlet, an outlet connected "to' said receptacle,a drainag'e outlet and a v'alve for said drainage outlet 1 including press'ure operable means for "normally closing-said'valve; conduit :said "drainage outlet 'in- I normally means connecting -s'aid compressor outlet with said-separator inlet "and s'ai'd prssure' operable means; a valve having an inlet connected "with said compressor outlet, a ventingputlet and 'a valve member for-controlling the flow of -fi'uid iro'm said valve min te "aid ventiiig outletpand inlet connected with having 'a ventin outlet; and means under the insaid chamber -unclerthe control :ofthe pressure of the lubricant of said "compressor lubricating system for operating said-valvemember.

'4. In a compressor system of the class described, the combination'of acompressor having 'an' outlet; a storage receptacle to which compressedfluid from said compressor is to be supplied; 'a' moisture outlet connected separator having an inlet, an to said receptacle, a drainage outlet,'a valve for'said drainage outlet including pressure 'ope'ra'blemeans for normally closing said valve, and a check valve for permitting the'fiow of fluid from said'separator inlet towards isaid c'ontrol'of said compressor operable toeifectclosing and opening of said last mentioned valve.

'5. In a compressor system of the class de- --scribed,' the combination of I a'compressor having an outlet; a storage receptacle to which compressed fluid from said compressor is to be-supplied; a-moisture separator having an inlet, an

outlet connected tosaid receptacle, a drainage outlet,a' valve for said drainage outlet including pressure operable means for normally closing said valve, conduitmeans connecting said separator inlet and said pressure operable means, anda check valv-e for permitting the flow oi -fluid from said separatorinlet towards said separator outlet; a valve having an inlet connected with said cor'npressor outlet and having' a venting outlet; a conduit connecting said separator inletand-said inlet of said lastmentioned'valve; and mean's' under the control of said compressor operable'to eilect closing andopening of said last mentioned valve.

6. In a compressor system of the class described, the combination of a compressor having anoutlet; a lubricating system for said compressor wherein'the lubricant is pressurized; a storage receptacle to which compressediiuid from said compressor is to be supplied; a moisture separator including a chamber having an inlet and having an outlet connected to said receptacle "and having a drainage outlet, a valve for said drainage outlet, pressure operable means for normally closing said valve, conduit means connecting 'saidcompressor outlet and said pressure operablemeans, passageway means connecting said chamber inlet and said conduit means, and a checkvalve in said passageway means for permitting'the flow offluid at a predetermined pressureinto said chamber; a valve having an inlet -connected tosaid conduitmeans, a venting outlet and a valve member for controlling thefiow offluid from said valve inlet to said venting out- 'let; andmeans including a piston chamber and a piston in said chamber under the control of the pressure of the lubricant of said compressor lubricatin system for operating said valve'memher.

7. A mois'ture-separator of the class described comprising a head, a base, a-tubular body between said 'head and said base providing a separating chamber, said base having a passageway extendingtherethrough provided with an inlet for compressed gasfrom which moisture istobe removed and an outletand having-a drainage conduit extending from said separating chamber tothe exterior thereofincluding a valve seat and a valve chamber; a 'valve member in said'*valve chamber, 'ipressure cperable means: in said base including 9. A separator according to claim 7, wherein said head and said base have heating means therein.

10. A separator according to claim 9, wherein said heating means are of theelectrical resistance type connected in a circuit including a ther- I mostatically controlled switch.

11. A moisture separator of the class described comprising a head, a base, a tubular body between said head and said base providing a separating chamber, said base having a passageway extending therethrough provided with an inlet for compressed gas from which moisture is to be removed and an upwardly facing outlet opening and pressure operable drainage means for said chamber, said head having a passageway provided with a downwardly facing inlet opening in alignment with said outlet opening and an outlet in communication with said chamber and having a second passageway extending from said chamber to the exterior, a connecting tube having its ends in communication with said outlet opening and said inlet opening respectively, means for providing a seal between said tube and said openings, means for providing a seal between the ends of said tubular body and said head and said base respectively, and means for securing said head and said base together to secure said tubular body and said connecting tube between said head and said base.

12. A moisture separator of the class described comprising a head, a base, a tubular body between said head and said base providing a separating chamber, said head having an inlet conduit and an outlet conduit in communication with said chamber, said base having a passageway extending therethrough provided with an inlet for compressed gas from which moisture is to be removed and an outlet in fluid flow communication with said inlet conduit, said base having a central bore extending through said passageway and formed with a reduced upper end communicating with said chamber and surrounded by a valve seat and having a bore extending outwardly from said central bore, a member in said central bore forming a closure for the lower end of said central bore and formed 'with a piston chamber at its upper end and having aperture means for establishing communication between said passageway and said piston chamber, a piston in said piston chamber, and valve means supported by said piston for engag ng said valve seat.

13. A moisture separator according to claim 12, wherein said base is formed with a bore adjacent the upper region of said central bore and an electrical heating unit is disposed in said last mentioned bore.

14. A moisture separator of the class described comprising a head, a base, a tubular body between said head and said base providing a separating chamber, said head having an inlet conduit including an inlet end for compressed gas from which moisture is to be removed, a downwardly extending outlet end bore and a nozzle section between said inlet end and said outlet end bore adapted to impart swirling motion to said gas entering said bore, a tube depending from said outlet end bore terminating in said chamber for accumulating said moisture from said gas, and a second tube surrounding said first tube and spaced therefro said head having an outlet conduit including an end in communication with said chamber at a point intermediate said tubes.

15. A moisture separator according to claim 14, wherein a check valve is positioned in said inlet conduit between said inlet end and said nozzle section, said check valve being constructed and I arranged to unseat in response to a predetermined pressure of the gas entering said inlet end.

16. A moisture separator according to claim 14, wherein said head is formed with a bore adjacent said outlet end bore and an electrical heating unit is disposed in said last mentioned bore.

17. A moisture separator comprising a head, a base, a tubular body between said head and said base providing a separating chamber, said head having a compressed gas inlet conduit formed with a centrally located vertical section in communication with said chamber and having an outlet conduit having a horizontal section, said base having a drainage outlet conduit including a centrally located vertical section in communication with said chamber and a horizontal section, valve means for controlling said drainage outlet, a horizontally disposed electrical heating unit in said head adjacent said vertical and said horizontal conduit sections, and a horizontally disposed electrical heating unit in said base adjacent said vertical and horizontal sections of said drainage outlet conduit.

18. A moisture separator according to claim 17, wherein said heating units are connected in a circuit, including a thermostatically controlled switch.

ALBERTUS E. SCHMIDLIN.

References Cited in the file of this patent UNITED STATES PATENTS 

